package ch89;

import java.util.InputMismatchException;
import java.util.Scanner;

public class Average {
    public static  void main(String[] args){


            Scanner scanner = new Scanner(System.in);
            double sum = 0;
            int count = 0;
            int number;
            while(true){
                number = scanner.nextInt();
                if(number==0){

                    break;
                }

                sum+=number;
                count++;

            }

            System.out.printf("平均%.2f%n", sum/count);


        }








}